CN105482118B - A kind of preparation method of semi-flexible polyether sulfone/ketone anion-exchange membrane - Google Patents

Abstract

The invention discloses a method for preparing a semi-flexible polyethersulfone/ketone anion-exchange membrane, in particular to a method for preparing a high-conductivity anion-exchange membrane for a fuel cell. The membrane material contains flexible fatty chains of different lengths in the repeating unit. Preparation method: 1) synthesis of polymer; 2) halomethylation of polymer; 3) preparation of semi-flexible polyethersulfone/ketone anion exchange membrane. Due to the introduction of aliphatic chains into the main chain of the polymer, the flexibility of the main chain is further improved, so that it has greater mobility, and strengthens the separation of hydrophilic and hydrophobic microphases to form better ion channels and reduce its swelling. The invention has simple preparation process and low cost, and the prepared anion exchange membrane has high conductivity and good stability, and is suitable for the application of alkaline fuel cell.

Description

A kind of preparation method of semi-flexible polyethersulfone/ketone anion exchange membrane

technical field

The invention relates to a preparation method of a semi-flexible polyethersulfone/ketone anion exchange membrane, in particular to a preparation method of a fuel cell high conductivity anion exchange membrane.

Background technique

Due to the current environmental and energy problems, the development of green energy with low environmental pollution and high energy conversion rate has become one of the urgent problems for human beings to solve. Due to its high conversion efficiency and clean characteristics, fuel cells have become a research hotspot in the field of new energy. As one of the most important components of the battery, the ion exchange membrane should have good ion conductivity and mechanical stability. Polyarylethersulfone (ketone) has become a good membrane material due to its excellent mechanical properties, corrosion resistance and thermal stability, and has attracted extensive attention in the field of fuel cell applications. However, although the cost of the traditional polyarylethersulfone (ketone) and its modified anion exchange membrane is low, the electrical conductivity is often low, and it is difficult to meet the high commercial demand. For example, British "International Journal of Hydrogen Energy" (International Journal of Hydrogen Energy, 2013, 38(25): 11067-11073.) reported a preparation method of a modified polyethersulfone anion exchange membrane. Polyethersulfone containing tetraphenylmethane in the repeating unit was synthesized, which increased the local concentration of ionic groups, but due to the strong rigidity of the chain, it was not conducive to the movement of the chain and could not form a good ion channel, resulting in its ion conduction The rate is still low (room temperature 25 mS/cm, theoretical IEC 2.56 mequiv g ^-1 ). At the same time, this film has a relatively large degree of swelling upon water absorption, which leads to its poor mechanical strength. Therefore, it is extremely important to synthesize new polymer membrane materials with better performance.

Contents of the invention

The purpose of the present invention is to provide a method for preparing a semi-flexible polyethersulfone/ketone anion exchange membrane. The preparation method modifies the traditional polyethersulfone/ketone and introduces a flexible chain into the repeating unit.

Technical scheme of the present invention:

The modified polyethersulfone/ketone polymer molecular chain is as follows:

A method for preparing a semi-flexible polyethersulfone/ketone anion-exchange membrane. First, polycondensation of diphenols containing flexible aliphatic chains to synthesize a modified polyethersulfone/ketone polymer is followed by chloromethylation and The semi-flexible polyethersulfone/ketone anion exchange membrane was prepared by ion functionalization; the synthetic route is as follows:

Wherein n=2～10.

1) Dihalogenated hydrocarbons and diphenols are synthesized under alkaline conditions into diphenol monomers containing flexible aliphatic chains, and recrystallized to obtain pure substances;

2) Preparation of polymer: Add difluoro monomers, diphenol monomers containing flexible aliphatic chains, and salt-forming agents at a molar ratio of 1:1:2 to 10 into the reactor, and then add water-carrying agents and solvents to prepare them. Form a mixed solution with a w/v of 5-20%, feed nitrogen, gradually raise the temperature to 140°C and reflux until the water is completely removed, then slowly raise the temperature to 165°C, keep the temperature constant for 15 hours, and cool to room temperature after the reaction is complete Pour the reaction product into ice water to precipitate a white fibrous polymer product; wash and soak the white fibrous polymer product with ethanol, and dry to obtain a polymer.

The reactor is a three-necked flask equipped with a Dean-Stark separator.

3) Halomethylation of polymers: Prepare a halogenated hydrocarbon solution with a w/v concentration of 0.5% to 5% polymer; add halomethylation reagents and catalysts, and stir for 3 to 12 hours at 0 to 40°C ; Cool to room temperature, pour into ethanol to precipitate, and wash repeatedly several times to obtain the chloromethylated product.

4) Functionalization of the chloromethylation product: dissolve the chloromethylation product with a solvent to form a solution with a concentration of 2% to 10%, and then add quaternary chloroform that is 1 to 10 times the amount of the chloromethylation product. The ammonium reagent M is reacted at 40-80° C. for 3-20 hours to obtain a casting solution. Place the casting solution on a flat plate by solution casting method, dry it, remove the film from the flat plate, place it in alkali solution for 24-48 hours, carry out ion exchange, wash with water until the pH is neutral, and obtain semi-flexible polyethersulfone / Ketone anion exchange membrane.

The halomethylation reagent is chloromethyl methyl ether, chloromethyl ethyl ether, chloromethyl butyl ether, chloromethyl octyl ether, bromomethyl methyl ether, bromomethyl ethyl ether, bromomethyl butyl ether or bromine Methyl octyl ether.

The catalyst is anhydrous zinc chloride, anhydrous ferric chloride, anhydrous aluminum chloride, anhydrous zinc bromide, anhydrous iron bromide, anhydrous aluminum bromide, metal zinc powder, metal iron powder, metal Aluminum powder, anhydrous tin tetrachloride, concentrated sulfuric acid, phosphoric acid or trifluoromethanesulfonic acid.

The halogenated hydrocarbon is selected from one of chloroform, 1,2-dichloroethane and 1,1,2,2-tetrachloroethane.

The drying temperature used in the solution pouring method is 50-80 DEG C, and the drying time is 24-36 hours; the lye is potassium hydroxide solution or sodium hydroxide solution.

The quaternization agent M is selected from one of trimethylamine aqueous solution, pentamethylguanidine, 1-methylimidazole, 2-methylimidazole, 1,2-dimethylimidazole and pyrrolidine.

The solvent is selected from one of N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide and dimethyl sulfoxide.

Beneficial effects of the present invention: In addition to the excellent mechanical properties of polyethersulfone/ketone, the semi-flexible polyethersulfone/ketone anion exchange membrane has high ion conductivity, low swelling degree and good alkali resistance stability It has a good application prospect in fuel cells. The membrane prepared by the method has high ion conductivity, cheap and abundant raw materials, and simple steps.

Description of drawings

Figure 1 shows the ion conductivity of 4C-PES-DImOH anion exchange membranes with different degrees of substitution as a function of temperature.

Figure 2 is the variation of swelling of 4C-PES-DImOH anion exchange membranes with different degrees of substitution with temperature.

detailed description

The specific implementation manners of the present invention will be further described below in conjunction with the accompanying drawings and technical solutions.

Example 1

Preparation of 4C-PES polymer: Dissolve 0.05 mol of 1,4 dibromobutane and 0.5 mol of hydroquinone in 95% ethanol, heat to reflux, add 0.15 mol of KOH ethanol solution dropwise, react for 5 hours, and synthesize 4C flexible diphenol monomer, recrystallized to obtain pure material. In a three-neck flask equipped with a nitrogen inlet and outlet device and a Dean-Stark separator, add 2.5425g of 4,4-difluorodiphenylsulfone (10mmol), 2.7432g of 4C flexible diphenol monomer (10mmol), 30mL of DMSO, 2.7624 g of potassium carbonate (20 mmol) and 15 mL of toluene. Gradually raise the temperature to 140°C and reflux for 5 hours until the water is completely removed in the form of toluene/water azeotrope, then the temperature rises slowly to 165°C, and the temperature is kept constant for 15 hours. The reaction was complete and cooled to room temperature. The product was slowly poured into ice water, and a white fibrous polymer product was precipitated. Wash and soak the product with ethanol and dry to obtain the polymer 4C-PES.

Preparation of CM-4C-PES polymer:

Into a 150 mL round bottom flask, 1 g of polymer 4C-PES and 100 ml of 1,1,2,2-tetrachloroethane were added. After the polymer was completely dissolved, the flask was placed in an oil bath at 40°C, and 5 mL of chloromethyl octyl ether and 1 molar equivalent of ZnCl ₂ were slowly added dropwise, and reacted for 4-8 hours. After the reaction, it was poured into 200mL ethanol to precipitate a white fibrous polymer product, which was thoroughly washed and dried in a vacuum oven at 30°C for 24 hours to obtain CM-4C-PES with different degrees of chloromethylation.

Preparation of 4C-PES-DImOH anion exchange membrane:

Dissolve 0.5g CM-4C-PES in 10mL DMSO, add 1,2-dimethylimidazole 1.5 times the amount of chloromethyl substance, and react at 80°C for 10h. After centrifugation, it was poured into a glass watch glass and placed in an oven at 60° C. for 24 hours to obtain a polymer film with a thickness of 100 μm. Put the membrane into 1M KOH solution for 48h, and then fully wash it to neutral with distilled water to obtain the anionic polymer membrane PES-DImOH. The ionic conductivity and swelling of membranes with different degrees of substitution are shown in the figure. When the IEC is 1.73mequiv/g, the ion conductivity at room temperature is 44.5mS/cm, the water absorption is 97.3%, and the swelling rate is 24.6%; at 60°C, the ion conductivity is 81.2mS/cm, the water absorption is 112.8%, and the swelling The rate is 30.7%. The tensile strength was 22.1 MPa, and the elongation at break was 13.2%. The prepared anion exchange membrane has good ion conductivity and mechanical strength, and can be used as a fuel cell alkaline ion exchange membrane.

Example 2

Preparation of 6C-PES polymer:

Similar to the preparation method of 4C-PES in Example 1, the difference is that the number of -CH ₂ - in the bisphenol monomer is 6 during the membrane forming process. Dissolve 0.05 mol of 1,6-dibromohexane and 0.5 mol of hydroquinone in 95% ethanol, heat to reflux, drop 0.15 mol of KOH in ethanol solution, and react for 5 hours to synthesize 6C flexible diphenol mono body, recrystallized to obtain pure monomer. In a three-necked flask equipped with a nitrogen inlet and outlet device and a Dean-Stark separator, 2.5425g of 4,4-difluorodiphenylsulfone (10mmol), 3.0232g of 6C diphenol monomer (10mmol), 30mL of DMSO, 2. 7624 g of potassium carbonate (20 mmol) and 15 mL of toluene. Gradually raise the temperature to 140°C and reflux for 5 hours until the water is completely removed in the form of toluene/water azeotrope, then the temperature rises slowly to 165°C, and the temperature is kept constant for 15 hours. The reaction was complete and cooled to room temperature. The product was slowly poured into ice water, and a white fibrous polymer product was precipitated. The product was washed with ethanol, soaked and then dried to obtain polymer 6C-PES. 1 g of 6C-PES polymer was dissolved in 100 ml of 1,1,2,2-tetrachloroethane. After the polymer was completely dissolved, the flask was placed in an oil bath at 40°C, and 5 mL of chloromethyl octyl ether and 0.2639 g of ZnCl ₂ were slowly added dropwise, and reacted for 6 hours. After the reaction was completed, it was poured into 200mL ethanol to precipitate a white fibrous polymer product, which was fully washed and then dried in a vacuum oven at 30°C for 24 hours to obtain CM-6C-PES with a chloromethylation degree of 118%. Take 0.5g of CM-6C-PES with this degree of substitution and dissolve it in 10mL of DMSO, add 1,2-dimethylimidazole 1.5 times the amount of chloromethyl substance, and react at 80°C for 10h. After centrifugation, it was poured into a glass watch glass and placed in an oven at 60° C. for 24 hours to obtain a polymer film with a thickness of 100 μm. Put the membrane into 1M KOH solution for 48h, and then fully wash it with distilled water until it is neutral to obtain the anionic polymer membrane 6C-PES-DImOH. When the IEC is 1.68mequiv/g, the ion conductivity at room temperature is 66.3mS/cm, the water absorption rate is 122%, and the swelling rate is 34.6%; at 60°C, the ion conductivity rate is 110mS/cm, the water absorption rate is 153%, and the swelling rate was 34.6%. The tensile strength at room temperature is 18.7 MPa, and the elongation at break is 16.4%.

Example 3

Preparation of 8C-PES polymer:

It is similar to the preparation method of 4C-PES in Example 1, except that the number of -CH ₂ - in the diphenol monomer is 8 during the membrane forming process. Dissolve 0.05 mol of 1,8-dibromooctane and 0.5 mol of hydroquinone in 95% ethanol, heat to reflux, add 0.15 mol of KOH in ethanol solution dropwise, and react for 5 hours to synthesize 8C flexible diphenol mono body, recrystallized to obtain pure monomer. In a three-neck flask equipped with a nitrogen inlet and outlet device and a Dean-Stark separator, 2.5425g of 4,4-difluorodiphenylsulfone (10mmol), 3.3232g of 8C diphenol monomer (10mmol), 30mL of DMSO, 2. 7624 g of potassium carbonate (20 mmol) and 15 mL of toluene. Gradually raise the temperature to 140°C and reflux for 5h until the water is completely removed in the form of toluene/water azeotrope, then the temperature rises slowly to 165°C, and the temperature is kept constant for 18h. The reaction was complete and cooled to room temperature. The product was slowly poured into ice water, and a white fibrous polymer product was precipitated. The product was washed and soaked with ethanol and then dried in a vacuum oven at 60°C for 24 hours to obtain the polymer 8C-PES. 1 g of 8C-PES polymer was dissolved in 100 ml of 1,1,2,2-tetrachloroethane. After the polymer was completely dissolved, the flask was placed in an oil bath at 40°C, and 5 mL of chloromethyl octyl ether and 0.2503 g of ZnCl ₂ were slowly added dropwise, and reacted for 3 hours. After the reaction, it was poured into 200mL ethanol to precipitate a white fibrous polymer product, which was fully washed and then dried in a vacuum oven at 30°C for 24 hours to obtain CM-8C-PES with a chloromethylation degree of 112%. Take 0.5g of CM-8C-PES with this degree of substitution and dissolve it in 10mL of DMSO, add 1,2-dimethylimidazole 1.5 times the amount of the chloromethyl substance, and react at 80°C for 10h. After centrifugation, it was poured into a glass watch glass and placed in an oven at 60° C. for 24 hours to obtain a polymer film with a thickness of 100 μm. Put the membrane into 1M KOH solution for 48h, and then fully wash it with distilled water until it is neutral to obtain the anionic polymer membrane 8C-PES-DImOH. When the IEC is 1.76mequiv/g at room temperature, the ion conduction rate is 71.6mS/cm, the water absorption rate is 146%, and the swelling rate is 50%; at 60°C, the ion conduction rate is 106.8mS/cm, the water absorption rate is 188%, and the swelling rate It is 64.4%, the tensile strength is 13.5MPa, and the elongation at break is 20.6%.

Example 4

Preparation of 4C-PEK polymer: similar to the preparation method of 4C-PES in Example 1, the difluoro monomer in polycondensation is 4,4-difluorobenzophenone. In a three-necked flask equipped with a nitrogen inlet and outlet device and a Dean-Stark separator, add 2.1820g of 4,4-difluorobenzophenone (10mmol), 2.7432g of 4C diphenol monomer (10mmol), and 30mL of DMSO , 2.7624 g of potassium carbonate (20 mmol) and 15 mL of toluene. Gradually raise the temperature to 140°C and reflux for 5 hours until the water is completely removed in the form of toluene/water azeotrope, then the temperature rises slowly to 165°C, and the temperature is kept constant for 15 hours. The reaction was complete and cooled to room temperature. The product was slowly poured into ice water, and a white fibrous polymer product was precipitated. The product was washed and soaked with ethanol and then dried in a vacuum oven at 60°C for 24 hours to obtain polymer 4C-PEK.

Preparation of CM-4C-PEK polymer:

Into a 150 mL round bottom flask, 1 g of polymer 4C-PEK and 100 ml of 1,1,2,2-tetrachloroethane were added. After the polymer was completely dissolved, the flask was placed in an oil bath at 40°C, and 5 mL of chloromethyl octyl ether and 1 molar equivalent of ZnCl ₂ were slowly added dropwise, and reacted for 10 h. After the reaction, it was poured into 200mL ethanol to precipitate a white fibrous polymer product, which was washed thoroughly and dried in a vacuum oven at 30°C for 24h to obtain CM-4C-PEK.

Preparation of 4C-PEK-DImOH anion exchange membrane:

Dissolve 0.5g CM-4C-PEK in 10mL DMSO, add 1,2-dimethylimidazole 1.5 times the amount of chloromethyl substance, and react at 80°C for 10h. After centrifugation, it was poured into a glass watch glass and placed in an oven at 60° C. for 24 hours to obtain a polymer film with a thickness of 100 μm. Put the membrane into 1M KOH solution for 48h, and then fully wash it to neutral with distilled water, and then obtain the anionic polymer membrane 4C-PEK-DImOH. When the IEC is 2.03mequiv/g, the ion conductivity at room temperature is 67.8mS/cm, the water absorption is 120.3%, and the swelling rate is 45.4%; at 60°C, the ion conductivity is 106.6mS/cm, the water absorption is 195.8%, and the swelling The rate is 54.2%. The tensile strength was 20.8 MPa, and the elongation at break was 27.4%. The prepared anion exchange membrane has good ion conductivity and mechanical strength, and can be used as a fuel cell alkaline ion exchange membrane.

Example 5

Preparation of 6C-PEK polymer:

Similar to the preparation method of 6C-PES in Example 2, the difluoro monomer in polycondensation is 4,4-difluorobenzophenone. Dissolve 0.05 mol of 1,6-dibromohexane and 0.5 mol of hydroquinone in 95% ethanol, heat to reflux, drop 0.15 mol of KOH in ethanol solution, and react for 5 hours to synthesize 6C flexible diphenol mono body, recrystallized to obtain pure monomer. In a three-neck flask equipped with a nitrogen inlet and outlet device and a Dean-Stark separator, 2.1820 g of 4,4-difluorobenzophenone (10 mmol), 3.0232 g of 6C diphenol monomer (10 mmol), 30 mL of DMSO, 2. 7624 g of potassium carbonate (20 mmol) and 15 mL of toluene. Gradually raise the temperature to 140°C and reflux for 5 hours until the water is completely removed in the form of toluene/water azeotrope, then the temperature rises slowly to 165°C, and the temperature is kept constant for 15 hours. The reaction was complete and cooled to room temperature. The product was slowly poured into ice water, and a white fibrous polymer product was precipitated. The product was washed and soaked with ethanol and then dried in a vacuum oven at 60°C for 24 hours to obtain polymer 6C-PEK. 1 g of 6C-PEK polymer was dissolved in 100 ml of 1,1,2,2-tetrachloroethane. After the polymer was completely dissolved, the flask was placed in an oil bath at 40°C, and 5 mL of chloromethyl octyl ether and 1 molar equivalent of ZnCl ₂ were slowly added dropwise, and reacted for 4 hours. After the reaction, it was poured into 200mL ethanol to precipitate a white fibrous polymer product, which was fully washed and then dried in a vacuum oven at 30°C for 24 hours to obtain CM-6C-PEK with a chloromethylation degree of 118%. Take 0.5g of CM-6C-PEK with this degree of substitution and dissolve it in 10mL of DMSO, add 1,2-dimethylimidazole 1.5 times the amount of the chloromethyl substance, and react at 80°C for 10h. After centrifugation, it was poured into a glass watch glass and placed in an oven at 60° C. for 24 hours to obtain a polymer film with a thickness of 100 μm. Put the membrane into 1M KOH solution for 48h, and then fully wash it to neutral with distilled water to obtain the anionic polymer membrane 6C-PEK-DImOH. When the ion exchange capacity is 1.35mequiv/g, the ion conductivity at room temperature is 37.5mS/cm, the water absorption is 56.7%, the tensile strength is 31.6MPa, the elongation at break is 10.3%, and at 60°C, the ion conductivity is 48.8 mS/cm, water absorption rate is 70.1%.

Example 6

Preparation of 8C-PEK polymer:

Similar to the preparation method of 8C-PES in Example 3, the difluoro monomer in polycondensation is 4,4-difluorobenzophenone. Dissolve 0.05 mol of 1,8-dibromooctane and 0.5 mol of hydroquinone in 95% ethanol, heat to reflux, add 0.15 mol of KOH in ethanol solution dropwise, and react for 5 hours to synthesize 8C flexible diphenol mono body, recrystallized to obtain pure monomer.

In a three-neck flask equipped with a nitrogen inlet and outlet device and a Dean-Stark separator, 2.1820 g of 4,4-difluorobenzophenone (10 mmol), 3.3232 g of 8C diphenol monomer (10 mmol), and 30 mL of DMSO , 2.7624 g of potassium carbonate (20 mmol) and 15 mL of toluene. Gradually raise the temperature to 140°C and reflux for 5h until the water is completely removed in the form of toluene/water azeotrope, then the temperature rises slowly to 165°C, and the temperature is kept constant for 18h. The reaction was complete and cooled to room temperature. The product was slowly poured into ice water, and a white fibrous polymer product was precipitated. The product was washed and soaked with ethanol and then dried in a vacuum oven at 60°C for 24 hours to obtain polymer 8C-PEK. 1 g of 8C-PEK polymer was dissolved in 100 ml of 1,1,2,2-tetrachloroethane. After the polymer was completely dissolved, the flask was placed in an oil bath at 40°C, and 5 mL of chloromethyl octyl ether and 1 molar equivalent of ZnCl ₂ were slowly added dropwise, and reacted for 2.5 hours. After the reaction, it was poured into 200mL ethanol to precipitate a white fibrous polymer product, which was fully washed and then dried in a vacuum oven at 30°C for 24 hours to obtain CM-8C-PES with a chloromethylation degree of 112%. Take 0.5g of CM-8C-PEK with this degree of substitution and dissolve it in 10mL of DMSO, add 1,2-dimethylimidazole 1.5 times the amount of chloromethyl substance, and react at 80°C for 10h. After centrifugation, it was poured into a glass watch glass and placed in an oven at 60° C. for 24 hours to obtain a polymer film with a thickness of 100 μm. Put the membrane into 1M KOH solution for 48h, and then fully wash it to neutral with distilled water to obtain the anionic polymer membrane 8C-PEK-DImOH. When the IEC is 0.94mequiv/g at room temperature, the ion conduction rate is 23.5mS/cm, the water absorption rate is 46%, and the swelling rate is 13%; the tensile strength is 37.7MPa, and the elongation at break is 20.6%. At 60°C, the ion conductivity is 36.8mS/cm, the water absorption is 78%, and the swelling rate is 18%.

Claims (10)

1. a preparation method of semi-flexible polyethersulfone/ketone anion-exchange membrane, is characterized in that, the steps are as follows: 1) Synthesizing dihalogenated hydrocarbons and diphenols into diphenol monomers containing flexible aliphatic chains under alkaline conditions, and recrystallizing to obtain pure substances; 2) Preparation of polymer: Add difluoro monomers, diphenol monomers containing flexible aliphatic chains, and salt-forming agents at a molar ratio of 1:1:2 to 10 into the reactor, and then add water-carrying agents and solvents to prepare them. Form a mixed solution with a w/v of 5-20%, and gradually raise the temperature to 140°C and reflux until the water is completely removed by introducing nitrogen gas, then slowly increase the temperature to 165°C, keep the temperature constant for 15 hours, and cool to room temperature after the reaction is completed; Pour the reaction product into ice water to precipitate a white fibrous polymer product; wash and soak the white fibrous polymer product with ethanol, and dry to obtain a polymer; Dean-Stark separator is housed in the described reactor; 3) Chloromethylation of polymers: Prepare a halogenated hydrocarbon solution with a w/v concentration of 0.5% to 5% polymer; add chloromethylation reagents and catalysts, and stir for 3 to 12 hours at 0 to 40°C ; Cool to room temperature, pour into ethanol to precipitate, and wash repeatedly several times to obtain the chloromethylated product; 4) Functionalization of the chloromethylated product: dissolve the chloromethylated product with a solvent to form a solution with a w/v concentration of 2% to 10%, and then add 1 to 10 times the amount of the chloromethylated product. A certain amount of quaternizing reagent M was reacted at 40-80°C for 3-20 hours to obtain the casting solution; the solution casting method was used to place the casting solution on a flat plate, dry it, remove the film from the flat plate, and place it in alkali In the solution for 24-48 hours, carry out ion exchange, wash with water until the pH is neutral, and obtain a semi-flexible polyethersulfone/ketone anion exchange membrane. 2. preparation method according to claim 1, is characterized in that, described chloromethylation reagent is chloromethyl methyl ether, chloromethyl ethyl ether, chloromethyl butyl ether or chloromethyl octyl ether. 3. according to the described preparation method of claim 1 or 2, it is characterized in that, described catalyst is anhydrous zinc chloride, anhydrous ferric chloride, anhydrous aluminum chloride, anhydrous zinc bromide, anhydrous bromine Iron oxide, anhydrous aluminum bromide, metal zinc powder, metal iron powder, metal aluminum powder, anhydrous tin tetrachloride, concentrated sulfuric acid, phosphoric acid or trifluoromethanesulfonic acid. 4. the preparation method according to claim 3 is characterized in that, described quaternization reagent M is trimethylamine aqueous solution, pentamethylguanidine, 1-methylimidazole, 2-methylimidazole, 1,2- Dimethylimidazole or pyrrolidine; The halogenated hydrocarbon is selected from one of chloroform, 1,2-dichloroethane and 1,1,2,2-tetrachloroethane. 5. The preparation method according to claim 1, 2 or 4, characterized in that the drying temperature used in the solution casting method is 50-80° C., and the drying time is 24-36 hours. 6. The preparation method according to claim 3, characterized in that, the drying temperature used in the solution casting method is 50-80° C., and the drying time is 24-36 hours. 7. according to the described preparation method of claim 1,2,4 or 6, it is characterized in that, described lye is potassium hydroxide solution or sodium hydroxide solution. 8. preparation method according to claim 3 is characterized in that, described lye is potassium hydroxide solution or sodium hydroxide solution. 9. preparation method according to claim 5 is characterized in that, described lye is potassium hydroxide solution or sodium hydroxide solution. 10. according to the preparation method described in claim 1,2,4,6,8 or 9, it is characterized in that, described solvent is selected from N-methylpyrrolidone, N,N-dimethylformamide, N, One of N-dimethylacetamide and dimethyl sulfoxide.